The Impact of Midodrine on Guideline-Directed Medical Therapy in Patients Admitted With Systolic Heart Failure.

ABSTRACT: Midodrine is occasionally used off-label to treat hypotension associated with advanced heart failure (HF); however, its association with changes in prescription of guideline-directed medical therapy (GDMT) is unknown. We sought to evaluate the effect of midodrine on the GDMT prescription pattern and clinical outcomes of patients with decompensated systolic HF. We retrospectively identified 114 patients admitted to our hospital in 2020 with decompensated systolic HF who were prescribed midodrine on discharge and compared them with 358 patients with decompensated systolic HF who were not prescribed midodrine. At 6 months, the midodrine group had more initiation or up-titration of beta blockers, renin-angiotensin-aldosterone system inhibitors, and sodium-glucose cotransporter-2 inhibitors compared with the nonmidodrine group. Survival at 6 months was similar between the 2 groups, but the midodrine group had more frequent rehospitalization for HF. Our findings suggest that midodrine is associated with improved GDMT in patients with decompensated HF but may be associated with worse prognosis.

Amiodarone for the Treatment of Arrhythmias in COVID-19 Patients Does Not Increase the Risk of Pulmonary Fibrosis: A Retrospective Cohort Study.

Amiodarone is a class III antiarrhythmic medication used to treat atrial and ventricular tachyarrhythmias. Pulmonary fibrosis from amiodarone use is a well-documented side effect. Pre-COVID-19 pandemic studies have shown that amiodarone-induced pulmonary fibrosis occurs in 1%-5% of patients and usually occurs between 12 to 60 months after initiation. The risk factors associated with amiodarone-induced pulmonary fibrosis include a high total cumulative dose (treatment longer than two months) and high maintenance dose (>400 mg/day). COVID-19 infection is also a known risk factor for developing pulmonary fibrosis and occurs in approximately 2%-6% of patients after a moderate illness. This study aims to assess the incidence of amiodarone in COVID-19 pulmonary fibrosis (ACPF). This is a retrospective cohort study with 420 patients with COVID-19 diagnoses between March 2020 and March 2022, comparing two populations, COVID-19 patients with exposure to amiodarone (N=210) and COVID-19 patients without amiodarone exposure (N=210). In our study, pulmonary fibrosis occurred in 12.9% of patients in the amiodarone exposure group compared to 10.5% of patients in the COVID-19 control group (p=0.543). In multivariate logistic analysis, which controlled for clinical covariates, amiodarone use in COVID-19 patients did not increase the odds of developing pulmonary fibrosis (odds ratio (OR): 1.02, 95% confidence interval (CI): 0.52-2.00). The clinical factors associated with the development of pulmonary fibrosis in both groups included a history of preexisting interstitial lung disease (ILD) (p=0.001), exposure to prior radiation therapy (p=0.021), and higher severity of COVID-19 illness (p<0.001). In conclusion, our study found no evidence that amiodarone use in COVID-19 patients increased the odds of developing pulmonary fibrosis at six-month follow-up. However, long-term amiodarone usage in the COVID-19 population should be based on the physician's discretion.

The Use of a Novel Heart Failure Agent in the Treatment of Pregnancy-Associated Cardiomyopathy.

Peripartum cardiomyopathy is an uncommon, pregnancy-related form of dilated cardiomyopathy that is associated with development of new-onset left ventricular dysfunction. Its etiology is presently unknown, but current standard of care involves the use of typical drug therapy for the treatment of heart failure. Pregnancy-associated cardiomyopathy (PACM) is a similar condition that refers to patients who develop such symptoms prior to the last month of pregnancy. We report the case of a nulliparous Caucasian female who develops early, severe PACM during her first pregnancy with postpartum persistence of New York Heart Association class II-III symptoms despite medical therapy. The use of the novel heart failure agent, sacubitril/valsartan (Entresto), is initiated with near-complete resolution of her symptoms.

Compressive optic neuropathy secondary to a lateral rectus muscle dermoid cyst.

A 48-year-old man presented 2 weeks after sudden OS vision loss. On examination, the patient had decreased OS visual acuity, an ipsilateral afferent pupil defect, and proptosis. MRI of the orbit with and without gadolinium showed a large, enhancing heterogeneous mass extending to the orbital apex. Uncomplicated resection was performed and pathology was consistent with a dermoid cyst. Postoperatively, the patient had improved visual acuity and minimal lateral rectus dysfunction. There are only 4 reported cases of dermoid cysts located within the lateral rectus muscle, albeit this is the first case describing a compressive optic neuropathy in the setting of an orbital dermoid cyst.

Lacrimal canaliculitis.

Canaliculitis is an uncommon, often misdiagnosed diagnosis because canaliculitis can mimic many other common ocular conditions. Canaliculitis should be appropriately diagnosed and treated to avoid recurrent inflammation and possible obstruction of the upper portion of the lacrimal system. This review will serve as a concise resource to aid in diagnosis and provide updated management options.

Probing carbon nanotube-surfactant interactions with two-dimensional DOSY NMR.

Two-dimensional diffusion ordered spectroscopy (2D DOSY) NMR was used to probe the micellar structure of sodium dodecyl sulfate (SDS) and sodium cholate (SC) in aqueous solutions with and without semiconducting and metallic single-walled carbon nanotubes (SWCNTs). The solutions contain SDS and SC at weight ratios of 1:4 and 3:2, the ratios commonly used to isolate semiconducting and metallic SWCNTs through density gradient ultracentrifugation (DGU). These results show that the coverage of surfactant on the semiconducting and metallic SWCNTs is nearly identical in the 1:4 surfactant mixture, and a lower degree of bundling is responsible for the greater buoyancy of semiconducting SWCNTs. In the 3:2 surfactant mixture, the metallic SWCNTs are only encapsulated in SC while the semiconducting SWCNTs remain encapsulated in a poorly packed two-surfactant micelle, leading to a large buoyant density difference between the electronic species. This work provides insight into future directions to increase the purity of semiconducting and metallic SWCNTs sorted through DGU and demonstrates the utility of 2D DOSY NMR in probing SWCNT-surfactant complexes.

Unrepaired tetralogy of fallot with major aortopulmonary collateral arteries in an adult patient.

Tetralogy of Fallot is characterized by a ventricular septal defect, a large, overriding aorta, subpulmonic stenosis, and right ventricular hypertrophy. These lesions can be associated with abnormal development of the pulmonary vasculature. This can include peripheral pulmonic stenosis, discontinuous pulmonary arteries, anomalous pulmonary venous return, and the development of aortopulmonary collateral vessels. Aortopulmonary collateral vessels develop to supply underperfused areas of the pulmonary bed and pose a unique and challenging problem at the time of surgical repair, which involves closure of the ventricular septal defect, relief of right ventricular outflow tract obstruction, maintenance of pulmonary valve competency when possible, and establishment of laminar pulmonary blood flow to all segments of the pulmonary bed. We describe a 36-year-old man with unrepaired tetralogy of Fallot with distinctive aortopulmonary collaterals, who underwent complete surgical repair with good outcome. Two-dimensional echocardiogram, cardiac magnetic resonance imaging, and cardiac catheterization each provided vital details allowing a stepwise approach to defining his unique anatomy for surgical correction.

Controlling the rate of electron transfer between a quantum dot and a tri-ruthenium molecular cluster by tuning the chemistry of the interface.

Ultrafast transient absorption measurements reveal that the rate of photoinduced electron transfer (PET) from colloidal CdSe quantum dots (QDs) to oxo-centered triruthenium clusters (Ru(3)O) depends on the structure of the chemical headgroup by which the Ru(3)O clusters adsorb to the QDs. Complexes comprising QDs and Ru(3)O clusters adsorbed through a pyridine-4-carboxylic acid ligand (nic-Ru(3)O) have an intrinsic PET rate constant of (4.9 ± 0.9) × 10(9) s(-1) whereas complexes comprising QDs and Ru(3)O clusters adsorbed through a 4-mercaptopyridine ligand (thiol-Ru(3)O) have an intrinsic PET rate constant of (36 ± 7) × 10(9) s(-1). Cyclic voltammetry measurements of nic-Ru(3)O and thiol-Ru(3)O yield reduction potentials vs. Ag/AgCl of -0.93 V for both clusters, and density functional theory calculations of the nic-Ru(3)O and thiol-Ru(3)O clusters yield internal reorganization energies for the cluster radical anion of -0.17 eV and -0.19 eV, respectively. The small differences in driving force and reorganization energy between the two complexes rule out these parameters as possible explanations for the factor-of-seven difference in the rate constants for PET. The difference in the observed rates of PET for the two complexes is therefore attributable to a difference in donor-acceptor electronic coupling, which, according to electronic structure calculations, is modulated by the torsional angle between the Ru(3)O core of the cluster and the functionalized pyridine ligand that bridges the cluster to the QD surface.

Model for adsorption of ligands to colloidal quantum dots with concentration-dependent surface structure.

A study of the adsorption equilibrium of solution-phase CdS quantum dots (QDs) and acid-derivatized viologen ligands (N-[1-heptyl],N'-[3-carboxypropyl]-4,4'-bipyridinium dihexafluorophosphate, V(2+)) reveals that the structure of the surfaces of the QDs depends on their concentration. This adsorption equilibrium is monitored through quenching of the photoluminescence of the QDs by V(2+) upon photoinduced electron transfer. When modeled with a simple Langmuir isotherm, the equilibrium constant for QD-V(2+) adsorption, K(a), increases from 6.7 × 10(5) to 8.6 × 10(6) M(-1) upon decreasing the absolute concentration of the QDs from 1.4 × 10(-6) to 5.1 × 10(-8) M. The apparent increase in K(a) upon dilution results from an increase in the mean number of available adsorption sites per QD from 1.1 (for [QD] = 1.4 × 10(-6) M) to 37 (for [QD] = 5.1 × 10(-8) M) through desorption of native ligands from the surfaces of the QDs and through disaggregation of soluble QD clusters. A new model based on the Langmuir isotherm that treats both the number of adsorbed ligands per QD and the number of available binding sites per QD as binomially distributed quantities is described. This model yields a concentration-independent value for K(a) of 8.7 × 10(5) M(-1) for the QD-V(2+) system and provides a convenient means for quantitative analysis of QD-ligand adsorption in the presence of competing surface processes.

Ligand-controlled rates of photoinduced electron transfer in hybrid CdSe nanocrystal/poly(viologen) films.

This paper describes a study of the rates of photoinduced electron transfer (PET) from CdSe quantum dots (QDs) to poly(viologen) within thin films, as a function of the length of the ligands passivating the QDs. Ultrafast (<10 ps), quantitative PET occurs from CdSe QDs coated with HS-(CH(2))(n)-COOH for n = 1, 2, 5, and 7 to viologen units. The observed decrease in the magnitude of the PET rate constant with n is weaker than that expected from the decay of the electron tunneling probability across extended all-trans mercaptocarboxylic acids but well-described by electron tunneling across a collapsed ligand shell. The PET rate constants for films with n = 10 and 15 are much slower than those expected based on the trend for n = 1-7; this deviation is ascribed to the formation of bundles of ligands on the surface of the QD that make the tunneling process prohibitively slow by limiting access of the viologen units to the surfaces of the QDs. This study highlights the importance of molecular-level morphology of donor and acceptor materials in determining the rate and yield of interfacial photoinduced electron transfer in thin films.

Simultaneous determination of the adsorption constant and the photoinduced electron transfer rate for a CdS quantum dot-viologen complex.

Transient absorption (TA) spectroscopy of solution-phase mixtures of colloidal CdS quantum dots (QDs) with acid-derivatized viologen molecules, N-[1-heptyl],N'-[3-carboxypropyl]-4,4'-bipyridinium dihexafluorophosphate (V(2+)), indicates electron transfer occurs from the conduction band of the QD to the LUMO of V(2+) after photoexcitation of a band-edge exciton in the QD. Analysis of the magnitude of the ground state bleach of the QD as a function of the molar ratio QD:V(2+) yields the QD-ligand adsorption constant, K(a) (4.4 × 10(4) M(-1)) for V(2+) ligands adsorbed in geometries conducive to electron transfer. The value of K(a), together with the measured rates of (i) formation of the V(+•) electron transfer product and (ii) recovery of the ground state bleach of the QD, enables determination of the intrinsic rate constant for charge separation, k(CS,int) ~ 1.7 × 10(10) s(-1), the rate for a single QD-V(2+) donor-acceptor pair. This analysis confirms previous reports that the number of ligands adsorbed to each QD is well-described by a Poisson distribution. This is the first report where the QD-ligand charge transfer and binding equilibria are quantitatively investigated simultaneously with a single technique.

Primary and secondary lacrimal canaliculitis: a review of literature.

Canaliculitis is an uncommon inflammation of the proximal lacrimal drainage system that is frequently misdiagnosed. It classically presents with symptoms of unilateral conjunctivitis, mucopurulent discharge, medial canthal inflammation, epiphora, and a red, pouting punctum. We summarize the literature on canaliculitis published from antiquity to the modern era and explore therapeutic options.

Charge carrier resolved relaxation of the first excitonic state in CdSe quantum dots probed with near-infrared transient absorption spectroscopy.

This manuscript describes a global regression analysis of near-infrared (NIR, 900-1300 nm) transient absorptions (TA) of colloidal CdSe quantum dots (QDs) photoexcited to their first (1S(e)1S(3/2)) excitonic state. Near-IR TA spectroscopy facilitates charge carrier-resolved analysis of excitonic decay of QDs because signals in the NIR are due exclusively to absorptions of photoexcited electrons and holes, as probe energies in this region are not high enough to induce absorptions across the optical bandgap that crowd the visible TA spectra. The response of each observed component of the excitonic decay to the presence of a hole-trapping ligand (1-octanethiol) and an electron-accepting ligand (1,4-benzoquinone), and comparison of time constants to those for recovery of the ground state bleaching feature in the visible TA spectrum, allow for the assignment of the components to (i) a 1.6 ps hole trapping process, (ii) 19 ps and 274 ps surface-mediated electron trapping processes, and (iii) a ∼5 ns recombination of untrapped electrons.